Platelets are parts of your blood that stick together to help form a clot. The stickier your platelets are, the greater your chance of having a heart attack. A clot in the wrong place can lead to a heart attack or stroke. Ticagrelor (Brilinta) keeps platelets from sticking together and it helps people from having a heart attack. The American College of Cardiology has recommended a combination of aspirin and Brilinta as one of the best treatments for the prevention of heart attacks, and death in patients who have had a heart attack or coronary stents. However, it is unknown if Brilinta may improve its work to keep platelets from sticking together giving a loading dose in patients already treated with Brilinta. A loading dose is a one-time increased dose of the same drug. The purpose of this study is to demonstrate whether the platelets of patients treated with Brilinta become less sticky when Brilinta is re-loaded.